ffof, ff trio pack, soil ph, auto flowers

So I just started a grow, using ffof with some of their nutes, not using yet tho since I'm only 2 weeks in, but my question is, do I have to worry about the ph of the soil if I'm using all of the ff lineup? Bad how would one go about checking the SOIL pH without going out and buying a soil ph probe. Do the nutes play a role in making the ph in the soil more acidic/alkaline, and if I'm using straight tap, left to sit out 24 hours, with no ppm meter read but a ph read of roughly 7, how would I adjust the ph in the soil accordingly? I've read ph up and down, but am very unfamiliar with all this as I'm just starting out. I just want the very best for my babies, any and all help is greatly appreciated.

Basically, should I buffer the ph of my nutes after mixing wth tap or should the ff trio pack just be used as is.. What do u guys think?

So just a question, why would you spend all that money on premium nutes and soil and then not want to get a ph meter? How can you buffer your water unless you read the soil? Trust me I've been there and it ain't pretty, most likely you won't have any ph issues, but if you do it will show up as deficiencies and you'll be chasing your tail trying to fix it up. My advice is to get a meter or a ph soil test kit.
Cheers..